1. Technical Field
Aspects of the present invention relate to a robot using crawlers as moving devices, and more particularly to a crawler robot having, on both sides of a robot main body, crawlers driven in a triangular form to thereby form a triangular crawler device, and further, including a small subordinate crawler device rotatably connected with the triangular crawler device by a link.
2. Related Art
Examples of the related art robots include stationary robots mainly installed in the production lines of plants, and movable robots equipped with moving devices of various types; the related art movable robots mainly adopt either a caterpillar type or a leg type moving system.
Generally speaking, vehicles travel by using tires as in the case of automobiles, or by using caterpillars formed of iron or rubber belts as in the case of tanks. The belts used in the latter type of traveling system are called crawlers (or crawler belts). In the case of traveling by using crawlers, the ground contact area is larger than in the case of traveling by using tires. Therefore, it is possible to markedly reduce the applied weight (ground contact pressure) per unit area. Thus, it is possible to prevent sinking of the vehicle body in a damp ground or a bad road, making it advantageously possible to secure a high level of traveling performance.
Movable robots are expected to be applied to rescue work and operations in extreme environments; thus, high mobility and high reliability are required of the traveling mechanism of a movable robot, which is expected to be capable of climbing over as high an obstacle as possible. For a movable robot to climb over a high obstacle, displacement of the center of gravity thereof is important, and, in this regard, various related art systems for movable robots of this type have been proposed.
JP 2005-335681 A discloses a robot having on both sides thereof crawlers arranged in a square form, and JP 08-133141 A discloses a crawler robot having one sprocket for driving a crawler belt, two sets of rotating wheels in each of which two rotating wheels are integrally rotatable around the same axis, and one triangular mechanism in which three rotating wheels are arranged at the apexes of an equilateral triangle so as to be rotatable around the center of gravity thereof; those are arranged at the apexes of a square which is of a configuration symmetrical with respect to a center line and which does not involve interference between the rotating motions of the above-mentioned components, around which the crawler belt is wrapped.
While capable of traveling on an irregular ground or the like, such a related art caterpillar type crawler robot as mentioned above involves a complicated mechanism to climb over, for example, a high obstacle, resulting in an increase in size and a problem in terms of energy consumption and mobility. Further, many crawler robots are of a structure vertically asymmetrical, so when turned upside down, they become incapable of operation.